S3-13 SESSION 3: FACIOCRANIOSYNOSTOSIS – PART I SURGICAL OUTCOMES OF COMBINED LEFORT III AND LEFORT I OSTEOTOMYc IMMEDIATE POST-SURGERY AND AT ONE YEAR FOLLOW UP

Introduction: The purpose of this study was to evaluate the surgical outcomes of combined LeFort III and I osteotomies in the treatment of craniofacial patients with severe midface hypoplasia. Methods: A single-institution retrospective review of all patients who underwent combined LeFort III/I surgery from 1980 to 2018 (38 years). Inclusion criteria included 1) Le Fort III/I surgery at skeletal maturity 2) lateral cephalograms at pre-surgical and one week post-surgery and 3) computerized and traditional surgical planning records. 15 consecutive patients met the inclusion criteria (11 male and 4 female patients). Of the 15 patients, 7 patients had one year follow-up records. The mean age at the time of the surgery was 19.1± 6.1 years (range 17 to 26 years). Patient diagnosis included: Crouzon (N=9), Pfeiffer (N=2), Apert (N=1), Antley-Bixler (N=1), fronto-nasal dysplasia (N=1) and cleidocranial dysplasia (N=1). All study patients underwent a standard subcranial LeFort III with repositioning using an intermediate splint followed by interposition bone graft and rigid fixation. After fixation of LeFort III segment, a LeFort I osteotomy was performed and a final splint was used to repositioned the LeFort I segment prior to rigid fixation. Lateral cephalograms were studied at pre surgery (T1), immediate one week post surgery (T2), and one year post surgery (T3). Results: Mean blood loss during surgery was 888 ± 800 ml and mean duration of surgery was 7.3 ± 3.3 hrs. The LeFort III segment was planned for a 7.6 ±2.2mm advancement measured at orbitale. The LeFort I segment was planned to advance a total of 12.1±5.2mm at A point and 12.1± 5.5mm at upper incisor edge. One week post-LeFort III/I advancement shows that the LeFort III segment was advanced 5.8 ±4.3mm anteriorly and displaced 2.6±4.3mm inferiorly measured at Orbitale. The LeFort I segment advanced a net total of 10.1 ± 3.4mm anteriorly, 3.8 ±5.4mm inferiorly at A point and 8.9±4.1mm anteriorly, 4.2 ±5.6mm inferiorly at upper incisor edge. ANB angle increased by 6.6±4.6 degrees from T1 to T2. At one year follow-up, ANB angle decreased by 1.3±1.5 degrees compared to T2. Additionally, when compared to T2, Orbitale advanced 0.37 ± 2.9mm, A Point decreased by 3.4±3.5mm, and upper incisor edge retracted 1.9±2.5 mm at T3 post surgery. Conclusion: Combined LeFort III and I advancement surgery significantly improved midface position and occlusal relationship in patients with midface hypoplasia. At one year follow up, LeFort III/I segments shows about 20% relapse at upper incisal edge and 35% at point A. However, patients still maintained a positive overjet and overbite. Overcorrection is recommended to compensate for the post-surgical relapse.